JP6636552B2 - Tissue removal catheter for body lumen - Google Patents

Description

(Citation of related application)
This application claims priority from US Provisional Application No. 61 / 736,169, filed December 12, 2012, the entirety of which is incorporated herein by reference.

(Scope of disclosure)
The present invention generally relates to a tissue removal catheter for a body lumen.

  Vascular diseases are often caused by the accumulation of atheroma-like substances on the inner wall of the vascular lumen, especially the arterial lumen of the peripheral and other vasculature, especially the peripheral arteries, known as atherosclerosis Bring state. Atherosclerosis occurs naturally as a result of aging, but can also be exacerbated by factors such as diet, hypertension, inheritance, vascular damage and the like. Atherosclerotic deposits can have a wide range of variable properties, some deposits are relatively soft, and others deposit fibrous and / or calcified. In the latter case, the deposits are often referred to as plaques.

  Vascular diseases include a variety of methods, including drugs, bypass surgery, and various catheter-based approaches, including those that rely on intravascular weight loss or removal of atherosclerotic or other substances that occlude blood vessels. Can be treated with Various methods have been proposed for cutting or removing material and removing such material from blood vessels, generally referred to as atherectomy. An atherectomy catheter intended to cut or remove material from a vessel lumen is advanced into and past an occlusive material to cut and separate such material from the vessel lumen. A rotatable cutting blade (or other tissue removal element) may be employed.

  It would be desirable to provide a catheter that can access the small tortuous region of a body lumen and, in a controlled manner, remove tissue and / or other occlusive materials from within the body lumen. In one case, it may be desirable to provide an atherectomy catheter that can facilitate the capture of atheroma-like material. Provided are catheters and methods for use in various body lumens, including but not limited to coronary, peripheral, and other arteries, and other body lumens.

  In one aspect, a catheter generally comprises an elongate catheter body configured for insertion into a body lumen of a subject. The catheter body has opposing distal and proximal ends, a longitudinal axis extending between the distal and proximal ends, and an internal passage extending along the longitudinal axis. The cutter is located generally at the distal end of the catheter body. The cutter has a proximal end portion, a distal end portion, and a longitudinal axis extending between the proximal and distal end portions. The cutter is rotatable with respect to the catheter body, generally about its longitudinal axis. The cutter is defined by an annular cutting edge at a distal end portion of the cutter for removing tissue from a body lumen and an inner surface of the cutter extending proximally from the annular cutting edge toward a proximal end portion of the cutter. An axial cavity, and tissue extending from the central cavity through the cutter and removed from the body lumen by the annular cutting edge, can pass proximally through the eccentric opening toward the internal passage of the catheter body; An eccentric opening. The eccentric opening is offset from the longitudinal axis of the cutter body.

  In another aspect, a catheter generally comprises an elongated catheter body configured for insertion into a body lumen of a subject. The catheter body has opposing distal and proximal ends and a longitudinal axis extending between the distal and proximal ends. The cutter is generally located at the distal end of the catheter body for rotation about the longitudinal axis of the catheter body. The cutter has a proximal end portion, a distal end portion, and a longitudinal axis extending between the proximal and distal end portions. The cutter has a cutting edge at a distal end portion of the cutter for removing tissue from a body lumen and a deployment mechanism operably connected to the cutter and catheter body for selectively deploying and retracting the cutter. And The deployment mechanism is operably connected to the cutter, the camming element enabling rotation of the cutter relative to the camming element, the camming element being axially movable with the cutter relative to the catheter body. A cutter housing hinged adjacent the distal end of the catheter body, the cutter housing generally pivotable about the hinge axis, transversely to the longitudinal axis of the catheter body, and the cutter window. And a cutter housing. The deployment mechanism drives the cutter housing such that proximal movement of the camming element relative to the catheter body and the cutter housing pivots about the hinge axis, so that the deployment mechanism opens, thereby causing the cutting edge to The distal movement of the camming element extending and exposed through the cutter window relative to the catheter body and the cutter housing drives the cutter housing to pivot about a hinge axis, such that the deployment mechanism closes, Thereby, the cutting edge is stored in the cutter housing and is configured not to be exposed.

  In yet another embodiment, a catheter generally comprises an elongated catheter body configured for insertion into a body lumen of a subject. The catheter body has opposed distal and proximal ends, a longitudinal axis extending between the distal and proximal ends, and an internal tissue transport passage extending along the longitudinal axis. The cutter is generally located at the distal end of the catheter body for rotation about the longitudinal axis of the catheter body. The cutter has a proximal end portion, a distal end portion, and a longitudinal axis extending between the proximal and distal end portions. The cutter includes an annular cutting edge at a distal end portion of the cutter for removing tissue from a body lumen and a tissue passage defined by an interior surface of the cutter extending proximally from the annular cutting edge. The passage has an inlet adjacent the annular cutting edge and an outlet extending through the cutter. A drive shaft is operatively connected to the proximal end portion of the cutter to selectively impart rotation to the cutter relative to the catheter body. The cutter adapter is operably connected to the cutter and defines an internal passage connecting the tissue passage of the cutter with the internal tissue transfer passage of the catheter body. The cutter adapter defines a shear edge proximal to and adjacent to the exit of the tissue passage. The cutter is rotatable relative to the shearing edge and cuts tissue passing proximally into the internal passageway through the outlet of the tissue passageway.

  In another aspect, a catheter generally comprises an elongated catheter body configured for insertion into a body lumen of a subject. The catheter body has opposed distal and proximal ends, a longitudinal axis extending between the distal and proximal ends, and an internal tissue transport passage extending along the longitudinal axis. The drive shaft extends axially through the internal tissue transfer passage and is configured for rotation about its longitudinal axis. The cutter is generally located at the distal end of the catheter body for rotation about the longitudinal axis of the catheter body. The cutter has a proximal end portion, a distal end portion, and a central longitudinal axis extending between the proximal and distal end portions. The cutter includes an annular cutting edge at a distal end portion of the cutter for removing tissue from a body lumen. The tissue passage is defined by an interior surface of the cutter extending proximally from the annular cutting edge and having an inlet adjacent the annular cutting edge and an outlet extending through the cutter. The stem at the distal end portion is operatively connected to a drive shaft to selectively impart rotation of the cutter about the central longitudinal axis of the catheter. The stem defines an eccentric camming portion that is radially offset from a central longitudinal axis of the cutter. The cutter adapter defines an internal passage connecting the tissue passage of the cutter with the internal tissue transfer passage of the catheter body. The cutter adapter includes an internal thread in the internal passage. The stem and the internal thread are configured such that the eccentric camming portion of the stem rides along the internal thread as the cutter is rotated by the drive shaft.

  In yet another aspect, a catheter generally comprises an elongated catheter body configured for insertion into a body lumen of a subject. The catheter body has opposed distal and proximal ends, a longitudinal axis extending between the distal and proximal ends, and an internal tissue transport passage extending along the longitudinal axis. The drive shaft extends axially through the internal tissue transfer passage and is configured for rotation about its longitudinal axis. The cutter is generally located at the distal end of the catheter body for rotation about the longitudinal axis of the catheter body. The cutter has a proximal end portion, a distal end portion, and a central longitudinal axis extending between the proximal and distal end portions. The cutter includes an annular cutting edge at a distal end portion of the cutter for removing tissue from a body lumen and a tissue passage defined by an interior surface of the cutter extending proximally from the annular cutting edge. The passage has an inlet adjacent the annular cutting edge and an outlet extending through the cutter. The protector is located just distal to the annular cutting edge of the cutter. The protective device is removed from the body lumen by covering at least about one-half of the circumferential portion of the annular cutting edge so that tissue located within the tissue passageway is distally from the cutter through the annular cutting edge. It is configured to prevent you from leaving.

Other objects and features will be in part apparent and in part pointed out hereinafter.
For example, the present invention provides the following items.
(Item 1)
A catheter for removing tissue from a body lumen,
An elongate catheter body configured for insertion into a body lumen of a subject, the catheter body comprising opposing distal and proximal ends, and the distal and proximal ends. A catheter body having a longitudinal axis extending therebetween and an internal passage extending along the longitudinal axis;
A cutter located generally at the distal end of the catheter body;
The cutter has a proximal end portion, a distal end portion, and a longitudinal axis extending between the proximal end portion and the distal end portion, the cutter generally having a longitudinal axis. The cutter body being rotatable with respect to the catheter body,
An annular cutting edge at the distal end portion of the cutter for removing tissue from a body lumen;
An axial cavity defined by an inner surface of the cutter extending proximally from the annular cutting edge toward the proximal end portion of the cutter;
An eccentric opening extending from the central cavity through the cutter;
The eccentric opening allows tissue removed from the body lumen by the annular cutting edge to pass proximally through the eccentric opening toward an internal passage of the catheter body, wherein the eccentric opening is A catheter offset from the longitudinal axis of the cutter.
(Item 2)
The catheter of claim 1, wherein the eccentric opening extends at an angle offset with respect to a longitudinal axis of the cutter.
(Item 3)
The catheter of claim 2, wherein the cutter has a transition that tapers toward the proximal end portion, and the eccentric opening extends through the transition of the cutter.
(Item 4)
The catheter of claim 1, wherein the eccentric opening extends at an angle offset from about 15 degrees to about 60 degrees from a longitudinal axis of the cutter.
(Item 5)
The catheter of claim 1, further comprising a drive shaft operably connected to the proximal end portion of the cutter to selectively impart rotation to the cutter.
(Item 6)
The catheter of claim 5, wherein the drive shaft is received within the internal passage of the catheter body, the drive shaft including an external thread for proximally transferring the removed tissue through the internal passage. .
(Item 7)
The cutter includes a stem at a proximal end portion thereof, the stem having a central axis generally coinciding with a longitudinal axis of the cutter, and the drive shaft configured to provide rotation to the cutter. 7. The catheter according to item 6, secured to the stem.
(Item 8)
The catheter of claim 7, wherein the stem includes an external thread for proximally transferring the removed tissue toward the drive shaft.
(Item 9)
The cutter further comprises a stationary shearing edge adjacent to the eccentric opening in the cutter, wherein the cutter is rotatable with respect to the stationary shearing edge to cut tissue passing proximally through the eccentric opening. , The catheter of item 1.
(Item 10)
The cutter has a shearing edge that partially defines the eccentric opening, such that the shearing edge of the cutter causes the cutter to rotate and shear tissue passing proximally through the eccentric opening. Item 10. The catheter of item 9, wherein the catheter overlaps the stationary shearing edge radially with respect to a longitudinal axis of the cutter.
(Item 11)
11. The article of claim 10, further comprising a shear member secured to the catheter body, wherein the shear member defines the stationary shear edge and the shear member has a bearing surface that engages an exterior of the cutter. catheter.
(Item 12)
The catheter of claim 11, wherein the stationary shear edge is defined on the bearing surface.
(Item 13)
The cutter includes a stem at a proximal end portion thereof, and the catheter further comprises a drive shaft operably connected to a stem of the cutter to selectively impart rotation to the cutter; 13. The catheter of item 12, wherein each of the drive shafts includes an external thread for transporting removed tissue proximally within the internal passage of the catheter body.
(Item 14)
Item 13 wherein the shear member has a countersink, wherein the countersink extends toward the bearing surface and forms part of an interior passageway of the catheter body, and wherein the stem is received in the countersink. A catheter according to claim 1.
(Item 15)
The countersink defines an internal shear edge in the shear member, and the threads of the stem interact with the internal shear edge when the cutter is rotating to remove removed material therebetween. 15. The catheter according to item 14, wherein the catheter is sheared and pinched.
(Item 16)
A deployment mechanism operably connected to the cutter and the catheter body for selectively deploying and retracting the cutter, wherein the deployment mechanism comprises:
A camming element operably connected to the cutter, wherein the camming element enables rotation of the cutter with respect to the camming element, wherein the camming element includes a cutter for rotating the cutter relative to the catheter body. A cam action element, which is axially movable with
A cutter housing hinged adjacent the distal end of the catheter body, wherein the cutter housing pivots about a hinge axis in a direction generally transverse to a longitudinal axis of the catheter body. And a cutter housing having a cutter window, wherein the deployment mechanism comprises:
Proximal movement of the camming element relative to the catheter body and the cutter housing drives the cutter housing to pivot about the hinge axis, such that the deployment mechanism opens, thereby causing the deployment mechanism to open. A cutting edge extends through the cutter window and is exposed;
Distal movement of the camming element relative to the catheter body and the cutter housing drives the cutter housing to pivot about the hinge axis, such that the deployment mechanism closes, thereby The catheter of claim 1, wherein a cutting edge is stored within the cutter housing and configured to be unexposed.
(Item 17)
The camming element includes a tongue extending distally with respect to the annular cutting edge of the cutter, the cutter housing including a closed ramp follower adjacent a distal end of the cutter housing; 17. A catheter according to item 16, wherein a closure ramp follower is adapted to move along the tongue as the camming element is moved distally to facilitate closure of the deployment mechanism. .
(Item 18)
The cutter defines a tissue passage extending from the annular cutting edge through the cutter, the camming element defining an internal passage, and the internal passage for removing removed tissue passing through the cutter. 18. The catheter according to item 17, wherein the catheter is in communication with the tissue passage of the cutter for receiving.
(Item 19)
Item 19. The catheter according to item 18, wherein the internal passage defined by the camming element is in communication with the internal passage defined by the catheter body.
(Item 20)
The tongue comprises a straight distal portion for guiding the cutter into the cutter housing, and an arcuate portion, wherein the arcuate portion covers the cutter and exposes the cutter. Item 18. The catheter according to item 17, allowing movement of the cutter housing.
(Item 21)
The cutter housing further comprises an open ramp follower, the open ramp follower being arranged to drive the cutter housing to expose the cutter in response to a proximal movement of the camming element. Item 17. The catheter according to item 16, wherein (Item 22)
22. The catheter according to item 21, wherein the open ramp follower and the closed ramp follower remain in operable contact with the camming element in all relative positions of the cutter housing and the camming element.
(Item 23)
The cutter further comprises a protection device disposed just distal to the annular cutting edge of the cutter, wherein the protection device covers at least about one-half of a circumferential portion of the annular cutting edge, thereby forming the body tube. The catheter of claim 1, wherein the catheter is configured to prevent tissue removed from the cavity and disposed within the axial cavity from exiting the cutter distally through the annular cutting edge. .
(Item 24)
A catheter,
An elongate catheter body configured for insertion into a body lumen of a subject, the catheter body comprising opposing distal and proximal ends, and the distal and proximal ends. A catheter body having a longitudinal axis extending between;
A cutter positioned generally at the distal end of the catheter body for rotation about a longitudinal axis of the catheter body, the cutter comprising a proximal end portion, a distal end portion, A longitudinal axis extending between the proximal end portion and the distal end portion, wherein the cutter includes a cutting edge at a distal end portion of the cutter for removing tissue from a body lumen. Including, cutter,
A deployment mechanism operably connected to the cutter and the catheter body for selectively deploying and retracting the cutter, the deployment mechanism comprising:
A camming element operably connected to the cutter, wherein the camming element enables rotation of the cutter with respect to the camming element, wherein the camming element includes a cutter for rotating the cutter relative to the catheter body. A cam action element, which is axially movable with
A cutter housing hinged adjacent a distal end of the catheter body, the cutter housing pivotable about a hinge axis in a direction generally transverse to a longitudinal axis of the catheter body. And a cutter housing having a cutter window, wherein the deployment mechanism comprises:
Proximal movement of the camming element relative to the catheter body and the cutter housing drives the cutter housing to pivot about the hinge axis, such that the deployment mechanism opens, thereby causing the deployment mechanism to open. A cutting edge extends through the cutter window and is exposed;
Distal movement of the camming element relative to the catheter body and the cutter housing drives the cutter housing to pivot about the hinge axis, such that the deployment mechanism closes, thereby A catheter, wherein the cutting edge is stored within the cutter housing and is configured not to be exposed.
(Item 25)
The camming element includes a tongue extending distally with respect to the annular cutting edge of the cutter, the cutter housing including a closed ramp follower adjacent a distal end of the cutter housing; A catheter according to item 24, wherein a closing ramp follower is adapted to move along the tongue as the camming element is moved distally to facilitate closing of the deployment mechanism. .
(Item 26)
The cutter defines a tissue passage extending from the annular cutting edge through the cutter, the camming element defining an internal passage, and the internal passage for removing removed tissue passing through the cutter. 26. The catheter according to item 25, wherein the catheter is in communication with the tissue passage of the cutter for receiving.
(Item 27)
27. The catheter according to item 26, wherein the internal passage defined by the camming element is in communication with the internal passage defined by the catheter body.
(Item 28)
The cutter housing further comprises an open ramp follower, the open ramp follower being arranged to drive the cutter housing to expose the cutter in response to a proximal movement of the camming element. 25. The catheter according to item 24, wherein: (Item 29)
29. The catheter according to item 28, wherein the open and closed ramp followers remain in operable contact with the camming element in all relative positions of the cutter housing and the camming element.
(Item 30)
The tongue comprises a straight distal portion for guiding the cutter into the cutter housing, and an arcuate portion, wherein the arcuate portion covers the cutter and exposes the cutter housing. 25. The catheter according to item 24, wherein the catheter is movable.
(Item 31)
A catheter,
An elongate catheter body configured for insertion into a body lumen of a subject, the catheter body comprising opposing distal and proximal ends, and the distal and proximal ends. A catheter body having a longitudinal axis extending therebetween and an internal tissue transport passage extending along the longitudinal axis;
A cutter positioned generally at the distal end of the catheter body for rotation about the longitudinal axis of the catheter body, the cutter comprising a proximal end portion, a distal end portion, A longitudinal axis extending between the proximal end portion and the distal end portion, wherein the cutter comprises an annular cut at the distal end portion of the cutter for removing tissue from a body lumen. An edge, and a tissue passage defined by an inner surface of the cutter extending proximally from the annular cutting edge, the tissue passage including an inlet adjacent the annular cutting edge, and an outlet extending through the cutter. Having a cutter,
A drive shaft operatively connected to the proximal end portion of the cutter for selectively imparting rotation to the cutter relative to the catheter body;
A cutter adapter operably connected to the cutter,
The cutter adapter defines an internal passage connecting the tissue passage of the cutter with the internal tissue transport passage of the catheter body, and the cutter adapter includes a shear proximal and adjacent to an outlet of the tissue passage. A catheter defining an edge, wherein the cutter is rotatable relative to the shearing edge and cuts tissue passing proximally into the interior passageway through an exit of the tissue passageway.
(Item 32)
A catheter,
An elongate catheter body configured for insertion into a body lumen of a subject, the catheter body comprising opposing distal and proximal ends, and the distal and proximal ends. A catheter body having a longitudinal axis extending therebetween and an internal tissue transport passage extending along the longitudinal axis;
A drive shaft extending axially through the internal tissue transfer passage and configured for rotation about its longitudinal axis;
A cutter positioned generally at the distal end of the catheter body for rotation about a longitudinal axis of the catheter body, the cutter comprising a proximal end portion, a distal end portion, A central longitudinal axis extending between the proximal portion and the distal end portion, the cutter comprising:
An annular cutting edge at the distal end portion of the cutter for removing tissue from a body lumen;
A tissue passage defined by an inner surface of the cutter, the tissue passage extending proximally from the annular cutting edge, the tissue passage having an inlet adjacent the annular cutting edge and an outlet extending through the cutter. When,
A stem at the distal end portion operably connected to a drive shaft, the stem selectively providing rotation of the cutter about a central longitudinal axis of the catheter, wherein the stem comprises the stem; A cutter, comprising: a stem defining an eccentric camming portion radially offset from a central longitudinal axis of the cutter; and
A cutter adapter defining an internal passage connecting the tissue passage of the cutter with the internal tissue transfer passage of the catheter body;
The cutter adapter includes an internal thread in the internal passage, wherein the stem and the internal thread cause the eccentric camming portion of the stem to mate with the internal thread as the cutter is rotated by the drive shaft. A catheter configured to ride alongside.
(Item 33)
A catheter,
An elongate catheter body configured for insertion into a body lumen of a subject, the catheter body comprising opposing distal and proximal ends, and the distal and proximal ends. A catheter body having a longitudinal axis extending therebetween and an internal tissue transport passage extending along the longitudinal axis;
A drive shaft extending axially through the internal tissue transfer passage and configured for rotation about its longitudinal axis;
A cutter positioned generally at the distal end of the catheter body for rotation about a longitudinal axis of the catheter body, the cutter comprising a proximal end portion, a distal end portion, A central longitudinal axis extending between the proximal portion and the distal end portion, wherein the cutter has an annular cutting edge at the distal end portion of the cutter for removing tissue from a body lumen. And a tissue passage defined by an inner surface of the cutter extending proximally from the annular cutting edge, the tissue passage having an inlet adjacent the annular cutting edge and an outlet extending through the cutter. Having a cutter,
A protection device located just distal to the annular cutting edge of the cutter;
The protection device may be configured to cover at least about one-half of a circumferential portion of the annular cutting edge so that tissue removed from the body lumen and disposed within the tissue passageway can be used to remove the annular cutting edge. A catheter configured to prevent distal exit of the cutter therethrough.

FIG. 1 is a partial perspective view of an embodiment of a tissue removal catheter that includes a removable handle attachable to the proximal end of the catheter. FIG. 2A is an enlarged partial side view of the distal end portion of the tissue removal catheter with the tissue removal catheter in a retracted position. FIG. 2B is similar to FIG. 2A, but the cutter housing has been removed to show hidden components. FIG. 3 is a longitudinal section of the distal end portion of the tissue removal catheter of FIG. 2A. FIG. 4A is an enlarged side elevation view of the distal end portion of the tissue removal catheter with the tissue removal catheter in a deployed position. FIG. 4B is similar to FIG. 4A, but the cutter housing has been removed to show hidden components. FIG. 5 is a longitudinal section of the distal end portion of the tissue removal catheter of FIG. 4A. FIG. 6A is an exploded perspective view of the distal end portion of the tissue removal catheter. FIG. 6B is an enlarged exploded perspective view of the cutter housing of the tissue removal catheter. FIG. 7 is an enlarged front perspective view of the cutter of the tissue removal catheter. FIG. 8 is an enlarged rear perspective view of the cutter of the tissue removal catheter. FIG. 9 is an enlarged longitudinal section of the cutter. FIG. 10 is a front perspective view of a second embodiment of a cutter for the tissue removal catheter of FIG. FIG. 11 is a front elevation view of the cutter of FIG. FIG. 12 is a longitudinal section of the cutter taken in the plane indicated by line 12-12 in FIG. FIG. 13 is a longitudinal section of the cutter taken at the plane indicated by line 13-13 in FIG. FIG. 14 is a front perspective view of a third embodiment of a cutter for the tissue removal catheter of FIG. FIG. 15 is a front elevation view of the cutter of FIG. FIG. 16 is a longitudinal section of the cutter of FIG. FIG. 17 is an enlarged exploded perspective view of the cutter and distal tube component of the tissue removal catheter of FIG. 1 including a second embodiment of the tissue removal catheter protection device. FIG. 18 is a longitudinal section taken through the assembled cutter, distal tube piece, and protector of FIG. FIG. 19 is an enlarged front elevation view of the distal tubing component of the tissue removal catheter of FIG. 1 with the external threads of the cutter stem shown in dashed lines. FIG. 20 is an enlarged rear elevation view of the distal tubing component of the tissue removal catheter of FIG. 1 with the external threads of the cutter stem shown in dashed lines. FIG. 21 is an enlarged longitudinal section similar to FIG. 3, with the cutter housing and catheter body removed therefrom and the drive shaft shown exploded for illustrative purposes. FIG. 22 is a front perspective view of a second embodiment of a distal tube component for the tissue removal catheter of FIG. FIG. 23 is a front elevational view of the distal tube piece of FIG. 22 with the external threads of the cutter stem indicated by dashed lines. FIG. 24 is a rear elevation view of the distal tube piece of FIG. 22, with the external threads of the cutter stem indicated by dashed lines. FIG. 25 is an enlarged front perspective view of a second embodiment of the proximal tubing component for the tissue removal catheter of FIG. FIG. 26 is a front elevation view of the proximal tubing component of FIG. 25, with the external threads of the drive shaft indicated by dashed lines. FIG. 27 is an enlarged longitudinal section similar to FIG. 21, including a second embodiment of the proximal and distal tube pieces. FIG. 28 is an enlarged side elevation view of the distal end portion of the second embodiment of the tissue removal catheter with the cutter of the tissue removal catheter in the deployed position. FIG. 29 is a longitudinal section of the distal end portion of the tissue removal catheter of FIG. 28. FIG. 30 is an enlarged front perspective view of the cutter of the tissue removal catheter of FIG. 28. FIG. 31 is an enlarged side elevation view of the cutter of FIG. 30. FIG. 32 is an enlarged longitudinal section of the cutter and distal tube piece of the tissue removal catheter of FIG. 28. FIG. 33 is a cross-sectional view of the cutter and distal tube piece taken through the plane indicated by line 33-33 in FIG.

  Corresponding reference characters indicate corresponding parts throughout the drawings.

  Referring now to the drawings, some embodiments of a tissue removal catheter for removing tissue from a body lumen are disclosed. In particular, the illustrated catheter embodiment is suitable for removing tissue from a body lumen, particularly for removing (ie, removing) plaque tissue from a blood vessel (eg, a peripheral artery or a peripheral vein). It is. However, features of the disclosed embodiments also include chronic total occlusion (CTO) of blood vessels, particularly peripheral arteries, and stenosis and stenosis of other body lumens such as the ureter, bile duct, respiratory tract, pancreatic duct, lymphatic vessel, and the like. It may also be suitable for treating other hyperplastic and neoplastic diseases in other body lumens. Neoplastic cell growth will often occur as a result of tumors surrounding and penetrating body lumens. Removal of such substances may therefore be beneficial for maintaining the patency of body lumens. The remaining discussion is directed to catheters for removing tissue from blood vessels and penetrating occlusions therein (eg, atheromatous or thrombotic occlusion material in arteries or other occlusions in veins), The teachings of the present disclosure are not limited to other types, including catheters for penetrating various occlusions, stenosis, or hyperplastic material in various body lumens and / or removing tissue therefrom. It should be understood that this applies equally to tissue removal catheters.

Referring now to FIGS. 1-9, a first embodiment of a catheter, and more specifically, a tissue removal catheter, is indicated generally by the reference numeral 10. Briefly, the tissue removal catheter 10 includes opposed proximal and distal ends, a central longitudinal axis LA ₁ (FIG. 2) extending between the distal and proximal ends, and generally a longitudinal length of the catheter body. An elongated tubular catheter body 12 having an internal tissue transfer passage 14 (FIGS. 3 and 5) extending along an axis. Referring to FIGS. 2-5, a rotatable cutter, generally indicated at 16, is operatively connected to the distal end of the catheter body 12 to remove tissue from a body lumen. In particular, in the illustrated embodiment, the cutter 16 is operatively connected to a cutter adapter, generally indicated at 18. A drive shaft 20 (FIGS. 3 and 5), including an external helical thread 22, drives the rotation of the cutter 16 and also proximally transports or moves the removed tissue within the tissue transport passage 14 of the catheter body 12. Let it. The deployment mechanism, shown generally at 24, includes a retracted position where the cutter is not exposed for cutting (FIGS. 1, 2A and 3) and a deployed position where the cutter is exposed for cutting (FIGS. 4A and 5). The tissue removal catheter 10 is configured between the two. As will be described in greater detail below, in the illustrated embodiment, the cutter adapter 14 functions as part of the deployment mechanism 24 and, with additional features, is configured as a tissue shearing member and includes a Facilitates proximal transfer of removed tissue.

  Still referring to FIG. 1, the catheter body 12 is configured (eg, sized and shaped) for intravascular introduction into a target artery, but as described above, the catheter body It may be configured for intraluminal introduction into a target body lumen other than the target artery. Although not shown, the catheter 10 may be configured for introduction of the catheter body 12 via a guidewire to a target site in the vasculature. In particular, the catheter 10 is configured for "over-the-wire" introduction when the guidewire channel extends completely through the catheter body 12, or "fast-change" introduction when the guidewire channel extends only through the distal portion of the catheter body. Can be done. In other cases, it may be possible to provide a fixed or integral coil edge or guidewire edge on the distal portion of catheter 10, or even eliminate the entire guidewire. Further, a flexible atraumatic distal edge (not shown) may be secured to the distal end of the illustrated catheter to facilitate insertion of the catheter. For convenience of illustration, it is to be understood that the guidewire is not shown in any of the embodiments, but can be incorporated into any of these embodiments.

  The dimensions and other physical characteristics of the catheter body 12 may vary depending on the artery (or other body lumen) to be accessed. The catheter body 12 is generally flexible, and in one embodiment, has a length in the range of 50 cm to 200 cm and a range of 1 French to 12 French (0.33 mm: 1 French), such as 3 French to 9 French. Inside diameter. The catheter body 12 may be constructed from an organic polymer, manufactured by an extrusion technique. Suitable polymers include polyvinyl chloride, polyurethane, polyester, polytetrafluoroethylene (PTFE), silicone rubber, natural rubber, and the like. Optionally, the catheter body 12 can be reinforced with braids, helical wires, coils, axial filaments, etc., to increase rotational strength, column strength, toughness, pushability, and the like. For example, the catheter body 12 may generally include a torque tube as is known in the art. The outer diameter of the catheter body 12 can be modified by thermal expansion and contraction using conventional techniques. It should be understood that the structure and dimensions of the catheter body may be other than those described without departing from the scope of the present invention.

  The catheter body 12 of this embodiment may include a guiding mechanism (not shown) for guiding the cutter to engage the body lumen wall during treatment. For example, the guide mechanism guides the cutter toward the wall of the body lumen and is biased (e.g., permanently deformed) into a double bend or double curve shape to improve treatment. Adjacent to and proximate to the cutter may form part of the catheter body. A suitable guidance mechanism is disclosed in U.S. Patent No. 7,708,749, the relevant teachings of which are incorporated herein by reference. In other embodiments, the guidance mechanism may take many other suitable forms. The catheter may not include a guiding mechanism without departing from the scope of the present invention.

Referring to FIGS. 3 and 5, as described above, the catheter 10 includes a rotatable cutter 16 and a drive shaft 20 to provide for rotation of the cutter. The drive shaft 20 extends along the tissue transport passageway 14 of the catheter body 12 and, optionally, axially therein (ie, to actuate the deployment mechanism 24), as described in greater detail below. generally, along the longitudinal axis LA ₁ of the catheter body) is movable. The distal end portion of the drive shaft 20 is generally operatively connected to the rotatable cutter 16 for selectively driving rotation of the cutter about the longitudinal axis LA ₁ of the catheter body 12. In the embodiment shown, the distal end portion of the drive shaft 20 is fixedly secured to the cutter 16. The shank of drive shaft 20 (ie, the portion of the drive shaft that does not include threads 22) is generally flexible and may include one or more coils (eg, stainless steel coils) or torque tubes (eg, (A polyimide tube with a layer of braided stainless steel wire embedded therein). The body of the drive shaft 20 can have very high torsional stiffness and sufficient tensile strength, but is generally laterally flexible. Any of a variety of other materials and structures may also be used, depending on the desired torque transmission, diameter, and flexibility.

  In the illustrated embodiment, a helical thread 22 external to the drive shaft 20 extends along the length of the drive shaft to proximally transport the removed tissue within the tissue transport passage 14 of the catheter body 12. Function as a transport mechanism for Thus, the threaded drive shaft 20 functions as an auger or screw conveyor, whereby rotation of the drive shaft imparts rotation of the helical thread 22 to proximally move tissue removed within the catheter body 12. Let it. In the illustrated embodiment, threads 22 are clockwise (drive shaft) such that clockwise rotation of drive shaft 20 (as viewed from the proximal end of drive shaft 20) transports tissue proximally. 20 from the proximal end). Tissue transfer passage 14 and drive shaft thread 22 may extend back to the proximal end portion of catheter body 12 and may flow into a tissue container (not shown). The tissue transfer passage 12 and the drive shaft thread 22 may stop short of the proximal end portion of the catheter body 12. The threads 22 may be formed on the drive shaft 20 in any suitable manner.

  In one embodiment shown in FIGS. 3 and 5, the cross-sectional dimension (e.g., inner diameter) of the tissue transfer passage 14 is small radially between the external threads on the drive shaft and the internal surface defining the tissue transfer passage 14. It slightly exceeds the outside diameter of the external thread 22 on the drive shaft 20 so that a gap (or play) exists. In this embodiment, the radial gap does not impede or hinder the rotation and axial movement of the drive shaft 20 within the tissue transfer passage 14 while at the same time substantially causing the tissue to engage with the threads 22 on the drive shaft 20 and the tissue. It is such as to block passage between it and an interior surface defining a transfer passage. For example, the diameter of the tissue transfer passage 14 can be about 0.001 inch (0.025 mm) to about 0.020 inch (0.508 mm) greater than the outer diameter of the external thread 22. It should be understood that other types of transfer mechanisms (e.g., suction devices, or other types of auger transfer mechanisms) may be used with the catheter 10 instead of the helical threads 22 on the drive shaft 20. It should also be understood that the transfer mechanism may be omitted without departing from the scope of the present invention. For example, a chamber may be provided proximal or distal to cutter 16 to store the removed tissue.

  Referring to FIG. 1, the proximal end of the drive shaft 20 is operatively connected to a cutter motor 30 (broadly, a cutter driver) to provide rotation of the drive shaft 20 relative to the catheter body 12. In one embodiment, cutter motor 30 is located within handle 32, which is removably connectable to the proximal end of catheter 10 (shown with cover removed in FIG. 1). For example, in addition to cutter motor 30, handle 32 may include a power source 34 (eg, a battery) for cutter motor 30, a microswitch (not shown) for activating the cutter motor, and a motor proximate drive shaft 20. A catheter connector 36 for operably connecting to the end portion may be housed. In some embodiments, the cutter motor 30 can rotate the drive shaft 20 at 1,000 rpm to 10,000 rpm or more, if desired. As will be described in more detail below, the handle 32 controls the axial movement of the drive shaft 20 to actuate the deployment mechanism 24 and the rotation of the drive shaft 20 and the cutter 16 via the cutter driver 30, such as the rotation of the drive shaft 20 and the cutter 16. It may include one or more input devices, such as lever 40, that control the primary movement. It should be understood that the drive shaft 20 can be driven in other ways without departing from the scope of the present invention.

As best seen in Figure 7-9, the rotatable cutter 16 has a proximal and distal end faces, the longitudinal axis LA ₂ extending therebetween. The cutter 16 includes a generally cylindrical distal cutting portion 42, a proximal stem 44 for connecting the cutter to the drive shaft 24 (broadly, a drive shaft connecting portion), and transitions between the distal cutting portion and the stem. And a portion 46. Distal cutting portion 42 has an outer cross-sectional dimension OD ₁ (eg, outer diameter) that is greater than outer cross-sectional dimension OD ₂ of stem 44 (eg, outer diameter), and the exterior of transition portion 46 is separated from the distal cutting portion It tapers (eg, neck down) longitudinally to the stem. For reasons explained below, the outer surface of the distal cutting portion 42 has a circumferential groove 48 formed therein. The cutter 16 can be formed as a single unitary structure or from separate components that are secured together in a suitable manner, such as welding, soldering, adhesives, mechanical interference fits, threaded engagements, etc. Can be formed. As a non-limiting example, cutter 16 may be comprised of steel, tungsten carbide, tungsten cobalt carbide, tungsten molybdenum carbide, silicon carbide, silicon nitride, ceramic, amorphous metal, or other material, and may be turned, ground, It can be manufactured by a method, including knitting, electrical discharge machining (EDM), laser cutting, heat treatment, precipitation hardening, casting, or other methods.

  Still referring to FIGS. 7-9, the distal cutting portion 42 of the cutter 16 is defined by an annular cutting edge 50 at its distal end and an inner surface of the cutter 16 extending from the cutting edge of the cutter to the stem 44. , An axial cavity 52. In one non-limiting example, the annular cutting edge 50 is beveled from the outer surface to the inner surface of the cutter to define a sharp distal cutting edge. The beveled annular cutting edge 50 creates a “negative angle of attack”. The cutting edge 50 can be formed separately from and attached to the distal cutting portion 42 of the cutter 16 or the cutting edge can be formed integrally with the distal cutting portion of the cutter. In the embodiment illustrated in FIGS. 7-9, the annular cutting edge 50 has a substantially smooth surface. The cutting edge can be of other configurations without departing from the scope of the present invention. For example, other configurations of the cutting edge are disclosed below with respect to FIGS. 10-16.

The stem 44, rotation of the drive shaft, so as to provide rotation of the cutter about its longitudinal axis LA _2, to connect the cutter to the distal end of the drive shaft 20 (i.e., the axis of rotation of the cutter, the center of the cutter Coincides with the vertical axis). In the illustrated embodiment, as shown in FIG. 9, the central longitudinal axis LA ₃ of the stem 44 is consistent with the central longitudinal axis LA ₂ of the cutter 116. The stem 44 defines a bore 62 having a central axis coincident with the central longitudinal axis of the stem to which the distal end of the drive shaft 20 is fixed. For example, the distal end of drive shaft 20 may be secured within bore 62 by soldering, welding, adhesive, interference fit, crimping, or other methods. In the illustrated embodiment, the stem 44 includes a helical external thread 64 that extends along the length of the stem and further facilitates proximal transport of the removed tissue, as described in more detail below. Including. In the illustrated embodiment (best shown in FIGS. 3 and 5), external threads 64 on stem 44 are aligned (or mated) with threads 22 on drive shaft 20 and run along drive shaft. To form a substantially continuous thread extending from the stem. In one embodiment, the pitch of stem threads 64 is the same as the pitch of drive shaft threads 22, but the pitch may be different. In another embodiment, as shown in FIGS. 10-13, stem 44 may have no external threads.

As described above, tissue removed from the body lumen by the cutting edge 50 passes proximally through the cutter 16 toward the tissue transfer passage 14 of the catheter body 12. In the embodiment shown, the cutter 16 has an eccentric opening 68 that communicates with the axial cavity 52 to allow the removed tissue to pass through the cutter. Eccentric opening 68 and axial cavity 52 together define a tissue passage extending through cutter 16. Thus, as can be seen in FIG. 5, as the tissue is removed, it enters the axial cavity 52 and then passes through the eccentric opening 68 and into the cutter adapter 18 where the stem threads 64 and / or Driveshaft threads 22 (or other transfer mechanism) can be captured and transferred proximally within tissue transfer passageway 14. Referring to FIG. 9, the eccentric opening 68 in the cutter 16 is offset with respect to the longitudinal axis LA ₂ (and rotation axis) of the cutter. Eccentric opening 68, when viewed in the proximal direction from the distal end of the cutter 16, the eccentric opening, extends around the vertical axis LA ₂ arcuately, is shaped so as not to intersect the longitudinal axis of the cutter . In the illustrated embodiment (should be the most 7-9), the eccentric aperture 68, the eccentric opening (as defined by the interior surface parallel to the axis AC ₁ transition portion 46), a cutter Extends through the tapered transition portion 46 of the cutter 16 so as to extend at an angle α ₁ that is not coincident with or parallel to the longitudinal axis LA ₂ (and the axis of rotation) of the cutter 16. As a non-limiting example, the offset angle α ₁ can be from about 15 degrees to about 60 degrees, and in one example, about 45 degrees, from the longitudinal axis LA ₂ (and rotation axis) of the cutter 16. It should be understood that the cutter 16 may be of other configurations in other embodiments of the catheter without departing from the scope of the present invention.

Referring to FIGS. 10-13, another embodiment of a cutter is indicated by reference numeral 16 '.
The present cutter 16 ′ is similar to cutter 16, and similar components are indicated by corresponding reference numerals with a dash. In this embodiment, the beveled annular cutting edge 50 ′
May include one or more raised elements 56 (eg, a crusher). In the illustrated embodiment, four raised elements 56 are formed on the beveled, annular cutting edge 50 ', while in other embodiments, more than four or less than four raised elements are provided. , May exist. During removal of tissue from the target body lumen, raised element 56 produces a hammer-like impact on the tissue to be removed as cutter 16 'is rotated. If the tissue to be removed has fragile properties (eg, is calcified), the tissue will be broken into smaller particles, thereby facilitating its removal. Repeated rotation of cutter 16 will produce repeated hammering of cutter ridge element 56 against the tissue to be removed. Raised element 56 is disclosed in US patent application Ser. No. 12 / 958,488, filed Dec. 2, 2010, the relevant teachings of the raised element disclosed therein being incorporated herein by reference. Be incorporated. The stem 44 'of the cutter 16' is also not threaded, unlike the stem 44 of the cutter 16 described above. However, the cutter 16 'may also be provided with threads.

  Referring to FIGS. 14-16, another embodiment of a cutter is shown at reference numeral 16 ″. The present cutter 16 '' is similar to cutter 16, and similar components are indicated by corresponding reference numerals with a double dash. In this embodiment, the annular cutting edge 50 "includes one or more grooves 58 (i.e., spiral grooves) that extend from a location adjacent the cutting edge to an interior surface that defines the axial cavity 52". In the illustrated embodiment, the annular cutting edge 50 '' also includes the raised elements 56 described above with respect to FIGS. 10-13, but the raised elements may be omitted in other embodiments. Groove 58 is shaped and arranged to drive tissue proximally into axial cavity 52 '' as tissue is removed from the body lumen. Stem 44 ″ is also threaded, like stem 44 of cutter 16.

  As described above, catheter 10 includes a deployment mechanism 24 for configuring cutter 16 between a retracted position (FIGS. 1-3) and a deployed position (FIGS. 4A, 4B, and 5). The deployment mechanism 24 is connected to a deployment adapter 70 at the distal end of the catheter body 12. For the purposes of this disclosure, deployment adapter 70 is considered a part of catheter body 12, and in particular, a part of the distal end of the catheter body. In the embodiment shown, deployment mechanism 24 includes a cutter housing 74 defining a cutter window 75 hinged to deployment adapter 70 at the distal end portion of catheter body 12.

Cutter adapter 18, in the axial direction relative to the cutter housing 74 (i.e., the proximal and distal) is movable, whereby the proximal movement of cutter adapter, pivoting about its hinge axis A _H Drive the cutter housing to open the deployment mechanism 24 and expose the cutting edge 50 through the cutter window 75 (FIG. 5), and distal movement of the cutter adapter causes the cutter housing to pivot about its hinge axis. To close the deployment mechanism so that the cutting edge is retracted into the cutter housing (FIGS. 2 and 3). The cutter adapter 18 is axially movable with respect to the cutter housing 74 (and the catheter body 12) by moving the drive shaft 20 in the axial direction, and imparts axial movement to the cutter 16. Therefore, the cutter adapter 18 moves in the axial direction together with the cutter 16, and can move in conjunction with the drive shaft 20. In one embodiment, the drive shaft 20 is axially movable with respect to the catheter body 12 by actuating the lever 40 on the handle 32, which also activates the motor 30 and the drive shaft and cutter Sixteen rotations can be driven.

  Referring to FIGS. 2-6B, in the illustrated embodiment, the cutter adapter 18 is connected to a cradle-shaped rotating bearing member 80 that receives and supports the cutter 16, a proximal tube component 76 and a distal tube (Together define an adapter tube or adapter tube assembly). Bearing member 80 is received within cutter housing 74 and is axially slidable therein. In particular, in the illustrated embodiment, the bearing member 80 has an external arc-shaped cross-section that is generally complementary to the internal arc-shaped cross-section of the cutter housing 74 such that the bearing member is nested within the cutter housing. Has a surface. In the illustrated embodiment, the components of the cutter adapter 18 are formed as separate components and secured together by any suitable method, such as adhesives, welding, fasteners, and the like. Alternatively, the optional components (including all of the components) can be integrally formed as a single integral component. For example, tube pieces 76, 78 may be formed as a single unitary component. Each component of the cutter adapter 18, including the distal tube component 78, the proximal tube component 76, the bearing member 80, and the cutter housing 74, can be formed from stainless steel or other biocompatible material.

The rotating bearing member 80 generally prevents the axial movement of the cutter relative to the cutter adapter such that the cutter adapter moves axially with the cutter, while generally preventing the longitudinal movement of the catheter body 12 relative to the cutter adapter 18. about axis LA _1, configured to allow rotation of the cutter 16. The rotating bearing member 80 also holds the cutter 16 in position relative to the cutter adapter 18 when the cutter is rotated by the drive shaft 20. To this end, the bearing member 80 is generally complementary to the outer arcuate cross-sectional shape of the distal tube component 78 and the annular cutting edge 50 of the cutter 16 for supporting the cutter and distal tube component. An internal support surface having an arcuate cross-sectional shape. In the illustrated embodiment, the bearing member 80 includes a pin 82 that is received in a circumferential groove 48 on the outer surface of the cutter 16. The cutter adapter 18, and more specifically, the rotating bearing member 80 includes a tongue 84 that extends distally with respect to the cutting edge 50. As explained below, the tongue 84 interacts with the closed ramp follower 88 of the cutter housing 74 when the cutter adapter 18 is moved distally to facilitate retraction of the cutter 16 within the cutter housing. . The rotary bearing member 80 can be of other configurations and types without departing from the scope of the present invention.

  With reference to FIGS. 3-5 and 21, the proximal and distal tubing components 76, 78, respectively, together form a portion of the cutter 16 (eg, the transition and proximal portions 46, 44 of the cutter) and the drive shaft. 20 defines an internal passage 86 in the cutter adapter 18 in which a portion (eg, the distal end portion of the drive shaft) is received. As shown in FIG. 21, the exterior of the proximal tubing component 76 has a transition portion 79a that tapers proximally from the rotating bearing member 80 and a distal end portion of the catheter body 12 into the tissue transfer passageway 14. A proximal portion 79b, received and connecting the internal passage 86 of the adapter tube assembly and the tissue transfer passage 14, is provided. As described below, the exterior of the proximal tube piece 76 interacts with the open ramp follower 90 of the cutter housing 74 when the cutter adapter 18 is moved proximally, thereby opening the deployment mechanism 24. Facilitate. Open ramp follower 90 and closed ramp follower 88 remain in operative contact with the camming element in all relative positions of the cutter housing and the camming element (as described below).

The cutter housing 74 is hinged to the deployment adapter 70 at its proximal end via a hinge connector 92 (eg, hinge pin, trunnion, integral hinge, etc.) on the deployment adapter 70 (see FIG. 6A). The hinge connector 92 allows the cutter housing 74 to extend and retract the cutter 16 as shown in FIGS. 2-5, generally in a direction transverse to the longitudinal axis LA ₁ of the catheter body 12. , The cutter adapter 18, and the cutter. An edge (not shown) of catheter 10 may be secured to a distal end of cutter housing 74 such that the edge moves with the cutter housing.

Drive shaft 20 is moved proximally, such as by moving lever 40 on handle 32, to open deployment mechanism 24 and thereby deploy cutter 16. As the drive shaft 20 is moved proximally, the open ramp follower 90 in the cutter housing 74 moves along the exterior of the cutter adapter 18 (more specifically, the exterior of the proximal tubing component 76) and the catheter body. The cutter housing 74 is pivoted (broadly, deflected) relative to 12 and about the hinge axis. As the cutter housing 74 deflects, the cutting edge 50 of the cutter 16 extends through a cutter window 75 in the cutter housing, thereby exposing the cutting edge 50 to the outside of the cutter housing. As shown in FIG. 4A, when the cutter 16 is in the deployed configuration, the longitudinal axis LA ₂ of the cutter extends at an angle α ₂ offset from the central longitudinal axis LA ₄ of the cutter housing 74. This offset angle alpha ₂ may be from about 5 degrees to about 15 degrees. As seen in FIGS. 4 and 5, in the deployed position, only one circumferential portion of the cutting edge 50 (ie, the exposed circumferential portion) extends through the window 75, while the remaining circumferential portion of the cutting edge Does not extend through the window and is not exposed (ie, the unexposed circumferential portion). The ratio of the exposed circumference to the unexposed circumference is the effective exposure of the cutting edge 50. In the embodiment shown, less than half of the circumference of the cutting edge 50 is exposed at any moment as the cutter 16 rotates, and thus the effective exposure of the cutting edge is less than 50%.

  With reference to FIGS. 2B and 4B, the illustrated embodiment is adapted to limit the proximal movement of the cutter adapter relative to the cutter housing 74 on the cutter adapter 18, and more specifically, on the exterior of the proximal tube piece 76. A stop 99 (only one stop is visible in FIGS. 2B and 4B). In the illustrated embodiment, the stop 99 is defined by a notch formed in the exterior of the proximal tubing component. In the embodiment shown, the distal end of the catheter body 12, and more specifically, the distal end of the deployment adapter 70, engages the stop 99 when the cutter 16 is fully deployed, Prevents further proximal movement of the adapter 18. Alternatively, the distal end of deployment adapter 70 engages stop 99 when attempting to move cutter adapter 18 proximally beyond its fully deployed position.

  To close the deployment mechanism, thereby retracting the cutter 16 into the retracted configuration (as shown in FIGS. 1-3), the drive shaft 20 is moved to its original position, such as by moving a lever 40 on the handle 32. Moved distally from the proximal position, which may also turn off cutter driver 30 and stop rotation of cutter 16. As the drive shaft 20 is moved distally and the cutter 16, and thus the cutter adapter 18, is moved distally, the closing ramp follower 88 in the cutter housing 74 is moved into the tongue 84 at the distal end of the cutter adapter. Moving along, thereby driving the cutter housing to pivot about the hinge axis toward the closed position. As the cutter housing 74 pivots toward the cutter 16, the cutting edge 50 reenters the cutter housing through the cutter window 75. When the cutter 16 is in its fully retracted position inside the cutter housing 74, the distal end of the tongue 84 is received in the tongue slot 98 and prevents pivoting of the cutter housing 74 about the hinge axis. I do. As the drive shaft 20 is moved proximally, the tongue 84 exits the tongue slot 98, causing the cutter housing 74 to pivot about the hinge axis. The shape of the tongue 84 and the closing ramp follower 88 first allows the cutter housing 74 to pivot (in response to retraction of the cutter 16), and then causes the cutter to move out of the cutter window 75 into the cutter housing. Allows to move in the axial direction inside. The opposite occurs when the cutter 16 is deployed. The cutter 16 first moves axially into the cutter window 75, and then the cutter housing 74 is then pivoted to expose the cutting edge 50. It should be appreciated that the force for both deployment and retraction of the cutter 16 is provided entirely by the user through movement of the cutter 16, cutter adapter 18, and drive shaft 20.

  As described above and as described in more detail below, in one embodiment, the removed tissue is passed through the cutter 16 (eg, into the axial cavity 52, through an eccentric opening 68 in the cutter). Move) proximally into the cutter adapter 18 where the removed tissue is captured and transferred proximally within the catheter 10 by the stem thread 64 and the drive shaft thread 22. Is desirable. To further facilitate proximal movement of the removed tissue, the illustrated catheter 10 also includes a protection device 100 (broadly, a tissue deflector) connected to a cradle-shaped bearing member 80, the protection device comprising: 100 blocks the removed tissue that has entered the axial cavity 52 from turning (ie, moving distally) and exiting the axial cavity through the distal end of the cutter 16. . The protector 100 is generally located just distal to the cutting edge 50 of the cutter 16 and extends radially inward from the bearing member 80 toward the cutter window 75 in the cutter housing 74 when the cutter is deployed. , Covers the unexposed circumferential portion of the annular cutting edge 50 located below the cutter window 75. In other embodiments, the protection device 100 may cover more than or less than the unexposed circumferential portion.

With reference to FIGS. 17 and 18, the protection device 100 may include an externally threaded auger member 101 that extends outwardly from a surface 100 a of the protection device opposite the cutting edge 50. As shown in FIG. 18, the auger member 101 extends through the annular cutting edge 50 and into the axial cavity 52. The auger member 101 matches the central longitudinal axis LA ₂ of the cutter 16. The terminal end 101 a of the auger member 101 is located within the axial cavity 52. The auger member 101 is stationary and the cutter 16 accumulates in the axial cavity and the removed tissue wrapped around the auger member directs proximally toward the eccentric opening 68 in the cutter. Rotate around the auger member 101 as would be done. It should be understood that the protection device 100 and / or the auger member 101 can be omitted from the catheter 10.

  As described in more detail below, in the embodiment illustrated in FIGS. 1-12, the cutter adapter 18 (or at least a portion thereof) constitutes a “cam actuating element” of the deployment mechanism 24 (ie, In addition to functioning as such), it constitutes (ie, functions as) a "shearing member". In at least some embodiments, the cutter adapter 18 constitutes a "shear member" and does not constitute a "cam actuating element", or otherwise forms part of a deployment mechanism, as described below. It should be understood that they may not form. Further, some other components may be camming elements, or camming elements may be omitted. Similarly, in at least some embodiments, the cutter adapter 18 may form a “cam actuating element”, or otherwise form part of a deployment mechanism, without forming a “shear member”. Please understand that it is good. Further, some other components may be shear members, or shear members may be omitted.

  The distal tube component 78 of the illustrated cutter adapter 18 constitutes a "shear member." Referring to FIGS. 19-21, in this embodiment, the distal tube piece 78 passes through the inner bearing surface 102 at its distal end portion and the proximal end, which engages the outer surface of the transition portion 46 of the cutter 16. , Extending toward the internal bearing surface and forming part of the internal passage 86 of the cutter adapter 18. (The internal bearing surface 102 is also visible in FIGS. 3 and 5, but not labeled, among other figures.) As seen in FIG. It has a generally conical shape corresponding to the conical shape of the outer surface of the transition portion 46. Circumferentially spaced channels 106 extend longitudinally through bearing surface 102 to form shear edges 108. In this embodiment, best seen in FIGS. 19-21, the distal tube piece 78 (acting as a “shear member”) extends in two longitudinal directions forming two diametrically opposed shear edges 108. Although including the channel 106, it should be understood that the distal tube piece 78 can have one shear edge or more than two shear edges without departing from the scope of the present invention. As can be seen in FIGS. 3 and 5 and can best be seen in FIG. 21, the cutter shear edge 110, which partially defines the eccentric opening 68 in the cutter 16, includes a shear edge 108 as the cutter rotates. Interacts with. That is, as tissue removed from a body lumen (eg, a blood vessel) passes through the eccentric opening 68 in the cutter 16, the removed tissue is sheared or cut between the respective shear edges 108, 110. . This shearing facilitates proximal movement of the removed tissue into the cutter adapter 18 and toward the stem thread 64 and / or the drive shaft thread 22. In the illustrated embodiment, the removed tissue is sheared between shear edges 108, 110 about every 0.5 rotation of cutter 16.

  Referring to FIGS. 19-21, countersink 104 is sized and shaped to receive cutter stem 44 of cutter 16. The longitudinal channel 106 also extends through an interior surface that defines a countersink 104 and forms a longitudinal shear edge 112 in the countersink 104. As described above, in this embodiment, the cutter stem 44 includes a helical external thread 64, which in this embodiment is a right-hand thread. External threads 64 on cutter stem 44 (as shown in dashed lines in FIGS. 19 and 20) countersink as cutter 16 rotates (ie, clockwise rotation as shown in FIGS. 10 and 11). Interacting with the shearing edge 112 at 104, shearing or pinching the removed material between them, facilitating proximal movement of the removed tissue within the cutter adapter 18. In this embodiment (best shown in FIGS. 19-21), the outer diameter of the stem thread 64 is such that there is a slight radial gap (ie, a small amount of play) between the stem thread and the shear edge 112. As shown in FIG. The radial gap does not impede or hinder rotation of the stem 44 in the countersink 104, while at the same time providing shear or pinching of the removed material between the stem thread 64 and the shearing edge 112 and being removed. It is like promoting proximal movement of the tissue.

  In this embodiment (as best seen in FIG. 21), the internal passage 86 defined by the proximal tube component 76 tapers proximally to a constant uniform diameter in the proximal portion 79b of the proximal tube component. Has a diameter at the transition portion 79a of the proximal tube component 76 (ie, the inner cross-sectional dimension of the proximal tube component). The tapered internal passage 86 in the transition 79a may allow tissue to pass between the internal surface of the transition of the proximal tube component and the stem and / or drive shaft threads without undergoing significant shear. As such, the outer diameter of stem thread 64 and / or drive shaft thread 22 is significantly larger. On the other hand, the diameter of the internal passage 86 in the proximal portion 79b of the proximal tube component 76 does not prevent or hinder the rotation of the drive shaft 20 in the proximal tube component 76, while at the same time substantially removing the removed tissue. It slightly exceeds the outer diameter of the drive shaft thread 22 so as to prevent it from passing between the drive shaft thread 64 and the inner surface defining the constant inner diameter of the proximal tube piece. Thus, the drive shaft 20 effectively functions as an auger or screw conveyor within the proximal portion 79b of the proximal tube piece 76. In another embodiment, the outer diameter of the portion of the drive shaft thread at transition 79a is such that the drive shaft 20 also tapers into the internal passage 86 such that it effectively functions as an auger or screw conveyor at transition 79a. May be tapered to correspond to In yet another embodiment, as in the embodiment illustrated in FIGS. 25-27, and as discussed below, the proximal tubing component may have some of the stem threads 64 and / or drive shaft threads 22 removed. The channel may have a substantially uniform inner diameter (i.e., substantially non-tapered) above the outer diameter, and the channel extends longitudinally through its inner surface to provide a shear edge similar to the shear edge 112 of the countersink 104. Can be defined.

Referring to FIGS. 22-27, a second embodiment of the proximal and distal tube components is indicated by reference numerals 76 'and 78'. A second embodiment of the distal tube component 78 'is shown in FIGS. 22-24 and 27, and a second embodiment of the proximal tube component 76' is shown in FIGS. 25 and 26. These embodiments of the proximal and distal tube components 76 ', 78' correspond to the proximal and distal tube components 76, 78 of the previous embodiment, respectively, and the respective tube components 76 ', 78 of the present embodiment. By replacing the ', each can be used with the catheter illustrated in FIGS. 1-21. The present proximal and distal tube parts 76 ', 78' are similar to the aforementioned proximal and distal tube parts 76, 78, respectively, and similar components are indicated by corresponding reference numerals, including dashes. . Generally, operation of the catheter, including one or both of the second embodiments of the proximal and distal tubing components 76 'and 78' for removing tissue from a body lumen, is substantially performed by the first
May be similar to the above exemplary operation.

Referring to FIGS. 22-24 and 27, one of the differences between the present distal tube component 78 'and the previously described distal tube component 78 is that the distal tube 78' In contrast to the shear edge 108, four circumferentially spaced apart extending longitudinally through the bearing surface 102 'and the inner surface of the distal tube piece and defining four shear edges 108' on the bearing surface 102 '. Four shearing edges 112 ′ that extend proximally into the distal tube piece 78 ′.
As shown in FIGS. 14 and 15, two of the four shear edges 112 'are defined by the intersection of the countersink 104' and two of the channels 114 'and the remaining of the four shear edges Are defined by the intersection of two adjacent channels 106 '. Shear edges 108 ', 112' may be formed in other ways without departing from the scope of the present invention. Similar to shear edge 108 in the first embodiment, shear edge 108 ′ interacts with cutter shear edge 110 to shear the removed tissue passing through eccentric opening 68 in cutter 16. However, in contrast to the first embodiment, the removed tissue is sheared in a quarter turn of the cutter 16. Further, similar to the shearing edge 112 in the first embodiment, the shearing edge 112 'interacts with the stem thread 64 to shear or pinch the removed tissue in the cutter adapter and to provide a threaded drive shaft. Facilitates proximal movement of tissue toward 20.

Referring to FIGS. 25-27, one of the differences between the present proximal tubing component 76 'and the first proximal tubing component 76 is that the proximal tubing component, along its length, Having a substantially uniform inner diameter (ie, substantially non-tapered) that exceeds the outer diameter of stem threads 64 and / or drive shaft threads 22. As shown in FIGS. 25 and 26, circumferentially spaced channels 114 (not shown in the first embodiment) extend longitudinally through the interior surface of the proximal tube piece 76 'and countersink 104 A shear edge 115 similar to the 'shear edge 112' is defined. More specifically, in the illustrated embodiment, these channels 114 extend longitudinally through the transition portion 79a 'of the proximal tubing component 76' having a tapered outer surface, while the channels extend through the catheter body 12 It does not extend through the proximal portion 79b 'of the proximal tubing component received within the distal end (eg, deployment adapter 70). The shear edge 108 'in the proximal tube piece 76' may be an extension of the shear edge 112 'of the countersink 104'. External threads 22 on drive shaft 20 interact with shear lip 108 as cutter 16 and drive shaft rotate, shearing or pinching tissue therebetween, and promoting proximal movement of the removed tissue. .

In an exemplary operation, catheter 10 is inserted into a body lumen (eg, an artery) such that cutter 16 is positioned adjacent a target site. Fluoroscopy or other imaging techniques may be used to facilitate placement of the catheter 10 within a body lumen. During placement of the catheter 10 in a body lumen, the deployment mechanism 24 is closed and the cutter 16 is in the stowed position. At the target site, the deployment mechanism 24 moves the lever 40 on the handle 32 proximally, providing proximal movement of the drive shaft 20 relative to the catheter body 12 and the cutter housing 74, thereby providing the cutter adapter 18 and The cutter 16 is also released, such as by being moved proximally relative to the cutter housing. As the cutter adapter 18 moves proximally, a tongue 84 at the distal end of the cutter adapter retreats from a tongue slot 98 in the cutter housing 74 and an open ramp follower 90 in the cutter housing moves the proximal tube. It moves along the outer surface of part 76. Thus, the cutter adapter 18, and more specifically, the proximal tube piece 76, acts as a camming element for opening the deployment mechanism 24. Proximal tube part 76, as an open lamp go ride along the follower 90, the cutter housing 74, about the hinge axis _{A H,} and pivot relative to the cutter adapter 18, the cutter 16 and catheter body 12, the cutter A portion of the cutting edge 50 extends through a cutter window 75 defined by the cutter housing. As described above, a guide mechanism (not shown) may guide the cutting edge 50 toward the wall of the body lumen, and the offset cutter housing 74 may also guide the cutter toward the wall of the body lumen. Can promote.

In one embodiment, deployment of cutter 16 using lever 40 also activates or turns on cutter motor 30 to provide rotation of drive shaft 20 and cutter. With the cutter 16 deployed and rotating, the catheter 10 is moved distally within the body lumen, and the rotating cutting edge 50 separates tissue (eg, from an artery) from the body lumen (eg, from an artery). Plaque). As the tissue is removed, the removed tissue travels through the annular cutting edge 50 into the axial cavity 52 in the cutter 16 and then into the eccentric opening 68. Using the catheter 10 illustrated in FIGS. 1-21, about every 0.5 rotation of the cutter 16, the cutter shear edge 110 passes over one of the shear edges 108 ′ of the inner bearing surface 102 and its Shear the removed material located at the shear location. The sheared tissue moves proximally within the cutter adapter 18, and more specifically, within the countersink 104, where the rotating stem thread 64 interacts with the shearing edge 112 in the countersink and removes it. The pinched or sheared tissue is stimulated to promote proximal movement of the tissue within the cutter adapter toward the drive shaft threads 22 and the tissue transfer passage 14 of the catheter body. Within the tissue transfer passageway 14, the removed tissue continues to be moved proximally by drive shaft threads 22 which function as an auger or conveyor transfer mechanism.

Using the catheter 10 illustrated in FIGS. 1-21 and replacing the respective proximal and distal tubing components 76, 78 with the proximal and distal tubing components 76 ', 78', respectively, the cutter shear edge 110 Shears the removed material located at one of the shearing edges 108 'of the inner bearing surface 102' and located at the shearing location. The sheared tissue is counter-sunk in the distal tube piece 78 '.
Moving proximally within 4 ', the rotating stem thread 64 interacts with the shearing rim 112' in the countersink to pinch or shear the removed tissue and into the proximal tube piece 76 '. To promote tissue proximal movement. Within the proximal tube piece 76 ', the rotating drive shaft thread 22
Interacts with the shearing edge 108 to pinch or shear the removed tissue and facilitate proximal movement of the tissue transfer passageway 14. Within the tissue transfer passageway 14, the removed tissue continues to be moved proximally by drive shaft threads 22 which function as an auger or conveyor transfer mechanism.

Using the lever 40 on the handle 32 to move the drive shaft 20 distally with respect to the catheter body 12 after completing passage through the target site and removing tissue debris from the body lumen. With the deployment mechanism 24 closed, the cutter motor 30 may be turned off (or, alternatively, the motor may remain on). As the drive shaft 20 is moved distally, the closure ramp follower 88 moves along the tongue 84, about the hinge axis A _H, driving the pivoting of the cutter housing 74 relative to the cutter adapter 18 and cutter 16 I do. When the cutter 16 is in its fully retracted position inside the cutter housing 74 (eg, as shown in FIGS. 1-3), the distal end of the tongue 84 is positioned within the tongue slot 98 in the cutter housing 74. The cutting edge 50 is received in the cutter housing and is not exposed. With the cutter motor 30 turned off (in one embodiment) and the cutter 16 in the retracted position, the catheter 10 is moved proximally within the body lumen to allow further passage through the target site. I do.

Referring to FIGS. 28-33, another embodiment of a catheter for removing tissue from a body lumen is shown generally at 210. This embodiment includes similar, if not identical, features to the aforementioned catheter 10. Components of this embodiment that are similar or identical to the components of the catheter 10 are indicated by the corresponding reference numerals with 200 added. The catheter 210 includes an elongated catheter body 212, which may be the same as the catheter body 12 described above. The other components of the present catheter 210, which may be the same as similar components of the catheter 10 in both structure and function, and thus will not be described in further detail, include a threaded drive shaft 220 and a deployment hinged to the adapter 270, the cutter housing 274 is pivotable about the hinge axis _{a H} (including closing and opening ramp follower 288,290), the bearing member 280 of the frame shape, the proximal tube part 276 including. As described below, the following components of the present catheter 210 are similar to similar components of the catheter 10, but these components differ in one or both of structure and function from the aforementioned components. . That is, the cutter 216 and the distal tube component 278 (and thus the cutter adapter 218, but the proximal tube component 276 and bearing member 280 are the same as the respective proximal tube component 76 and bearing member 80).

Referring to FIGS. 31 and 32, the cutter 216 has a proximal and distal end faces, and a central longitudinal axis LA ₅ extending therebetween. The cutter 216 includes a generally cylindrical distal cutting portion 242, a proximal stem 244 for connecting the cutter to the drive shaft 220 (broadly, a drive shaft connecting portion), and a generally intermediate portion between the distal cutting portion and the stem. And a cylindrical bearing engaging portion 245. The distal cutting portion 242 has an outer cross-sectional dimension OD ₄ stem 244 (e.g., outer diameter) greater than the outer cross-sectional dimension OD ₃ (e.g., outer diameter) has, outside the bearing engaging portion 245, distal It has a cut portion and a step. The cutter 216 may be formed as a single unitary structure or separate components secured together in a suitable manner such as welding, soldering, adhesive, mechanical interference fit, threaded engagement, etc. Can be formed from As a non-limiting example, cutter 216 can be made of steel, tungsten carbide, tungsten cobalt carbide, tungsten molybdenum carbide, silicon carbide, silicon nitride, ceramic, amorphous metal, or other material, and can be turned, ground, fired, It can be manufactured by methods including kneading, electrical discharge machining (EDM), laser cutting, heat treatment, precipitation hardening, casting, or other methods.

Referring to FIGS. 30-33, the distal cutting portion 242 of the cutter 116 includes an annular cutting edge 250 at its distal end. Cyclic cutting edge 250 is a central longitudinal axis LA ₅ coaxial direction of the cutter 216. In one non-limiting example, the annular cutting edge 250 is beveled from the outer surface to the inner surface of the cutter 216 to define a sharp distal cutting edge. The beveled annular cutting edge 250 creates a “negative angle of attack”. The beveled annular cutting edge 250 may include raised elements (eg, crushers) similar to those described above with respect to FIGS. 1-13, and / or grooves similar to those described above with respect to FIGS. 14-16. . The cutting edge 250 can be formed separately from and attached to the distal cutting portion 242 of the cutter 216, or the cutting edge can be integrally formed with the distal cutting portion of the cutter. The cutting edge can be of other configurations without departing from the scope of the present invention.

Still referring to FIGS. 30-33, stem 144 defines a bore 162 to which the distal end of drive shaft 120 is secured (as shown in FIG. 29). For example, the distal end of drive shaft 220 may be secured within bore 262 by soldering, welding, adhesive, interference fit, crimping, or other methods. Stem 244 and bore 262 have matching central longitudinal axes, both indicated by reference letter LA ₆ (see FIG. 31). For reasons described below, the central longitudinal axis of the stem 244 and the bore 262, a cutter 216 (and the annular cutting edge 250) is radially offset from the central longitudinal axis LA ₅ of. Thus, the rotation axis of the drive shaft 220 in the stem 244, a cutter 216 (and the annular cutting edge 250) is radially offset from the central longitudinal axis LA ₅ of. As described below, the axis of rotation of the drive shaft 220 at the stem 244 is radially offset from the central longitudinal axis LA ₅ of the cutter 216 (and the annular cutting edge 250), but the rotation of the drive shaft is It gives the rotation of the cutter and the annular cutting edge about the longitudinal axis LA ₅ of the cutter (i.e., the axis of rotation of the cutter is consistent with the longitudinal axis LA ₅ cutter). In the illustrated embodiment, the offset stem 244 has a groove 263 (FIGS. 30, 31, and 33) extending along the length of the stem, as described below, so that tissue exits the cutter 216. Facilitate proximal movement of tissue as it goes.

29 and 32, the cutter 216 has an eccentric passage 253 (broadly, a tissue passage) extending from the annular cutting edge 250 through the stem 244. As shown in FIG. 32, the eccentric passage 253 has a central axis AC ₂ that is angular offset from the central longitudinal axis LA ₅ of the cutter 216. Accordingly, tissue removed from a body lumen (eg, a blood vessel) by cutting edge 250 passes through cutter 216 and enters cutter adapter 218 via eccentric passage 253. Center _{C 1} is offset from the longitudinal axis LA ₅ of the cutter 216. Central axis AC ₂ eccentric passage 253, may be about 5 degrees to about 20 degrees, by an angle alpha _3, may be an angle offset from the central longitudinal axis LA ₅ of the cutter 216. Eccentric opening 253 intersects the longitudinal axis LA _5. This can be accomplished due to the offset of stem 244. As a result, the eccentric openings 253 can be larger than the eccentric openings 68 in the arrangement shown in FIG.

Referring to FIG. 32, the cutter 216 includes a distal tube component 278 of the cutter adapter 218 such that the bearing engagement portion 245 engages the distal end of the distal tube component and the inner surface 220 of the distal tube component. Received within Thus, the distal tube component 278, the cutter 216 makes it possible to rotate about its central longitudinal axis LA ₅ with respect to the distal tube part 278 (including the other components of the cutter adapter 218), Functions as a rotating bearing. Thus, the rotation axis of the drive shaft 220 in the stem 244, a cutter 216 (and the annular cutting edge 250) but is radially offset from the central longitudinal axis LA ₅ of the cutter and the annular cutting edge is substantially cutter rotates about the longitudinal axis LA ₅ of. Otherwise, the cutter 216 will rotate about the central longitudinal axis LA ₆ of the stem 244 and move the cutting edge along the elliptical path relative to the catheter body 212 (ie, rock).

With reference to FIGS. 29 and 32, the distal tube component 278 includes an internal helical thread 215 that extends along the length of the distal tube component. Since the stem 244 is radially offset from the axis of rotation of the cutter 216 (which coincides with the central longitudinal axis LA _{5 of the} cutter), the stem of the cutter eccentrically orbits as the stem is rotated by the drive shaft 220. At, ride along the internal thread 215. The interaction of stem 244 and thread 215 drives proximal movement of the removed tissue disposed within distal tube piece 278. In other words, stem 244 functions to press the removed tissue in distal tube piece 278 against internal thread 215, thereby moving the removed tissue proximally along the thread. .

  In an exemplary operation, catheter 210 may be used in the same manner as described above for catheter 10. However, instead of the stem 244 of the cutter 216 having external threads to facilitate proximal movement of the removed tissue, the interaction of the internal threads 215 of the distal tube piece 278 and the eccentric stem 244 is described above. As such, it facilitates proximal migration of the removed tissue.

  Having described the embodiments of the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

  When introducing an element of the invention or a preferred embodiment thereof, the articles "a", "an", "the", and "said" are intended to mean one or more of the elements. The terms "comprising", "including", and "having" are intended to include and mean that there may be additional elements other than the listed elements. You.

  Since various changes can be made in the above arrangements, products and methods without departing from the scope of the invention, all content contained in the above description and shown in the accompanying drawings is illustrative. It is intended to be interpreted and not in a limiting sense.

Claims (8)

A catheter,
An elongate catheter body configured for insertion into a body lumen of a subject, the catheter body comprising opposing distal and proximal ends, and the distal and proximal ends. A catheter body having a longitudinal axis extending therebetween and an internal tissue transport passage extending along the longitudinal axis;
A drive shaft extending axially through the internal tissue transfer passage, the drive shaft being configured for rotation about its longitudinal axis;
For rotation about the longitudinal axis of the front Symbol catheter body, a cutter that is located at the distal end of the previous SL catheter body, wherein the cutter includes a proximal end portion, a distal end portion, A central longitudinal axis extending between the proximal portion and the distal end portion, the cutter comprising:
An annular cutting edge at the distal end portion of the cutter for removing tissue from a body lumen;
A tissue passage defined by an interior surface of the cutter, wherein the tissue passage extends proximally from the annular cutting edge, the tissue passage extending through an inlet adjacent the annular cutting edge, and through the cutter; An extending outlet, the tissue passage having a central axis angularly offset from the central longitudinal axis of the cutter, the tissue passage being configured to transfer the tissue obliquely outward in a radial direction. A tissue passage,
An eccentric stem at the proximal end portion of the cutter, wherein the eccentric stem is operatively connected to the drive shaft, the eccentric stem rotating the catheter about the central longitudinal axis. An eccentric stem, selectively provided to a cutter, the eccentric stem having a longitudinal axis radially offset from a central longitudinal axis of the cutter;
A cutter adapter defining an internal passage connecting the tissue passage of the cutter with the internal tissue transfer passage of the catheter body;
The cutter adapter includes an internal thread in the internal passage, the eccentric stem and the internal thread causing the eccentric stem to ride along the internal thread as the cutter is rotated by the drive shaft. Wherein the eccentric stem presses the tissue against the internal thread within the internal passage of the cutter adapter and transfers the tissue proximally along the internal thread. And thereby transporting said tissue toward said internal tissue transport passage of said catheter body.   The catheter of claim 1, wherein the tissue passage extends through the eccentric stem.   The catheter of claim 1, wherein the cutter adapter includes a distal portion, the distal portion defining the internal thread.   The catheter of claim 3, wherein the cutter is received within the distal portion of the cutter adapter.   The catheter of claim 4, wherein the cutter includes a cylindrical bearing portion that engages the distal portion of the cutter adapter to allow rotation of the cutter relative to the cutter adapter.   The catheter of claim 1, wherein the internal thread extends along a length of the distal portion of the cutter adapter.   The catheter of claim 1, wherein the drive shaft includes external threads.   The catheter of claim 1, wherein the eccentric stem has a groove extending along a length of the stem.